欢迎来到天天文库
浏览记录
ID:14425870
大小:11.71 MB
页数:69页
时间:2018-07-28
《hsdpa principles seminar》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、HSDPAPrinciplesSeminarCorradoCarbone-RO/QoSSouth2Agenda3.ChannelStructure2.Architecture1.Overview5.InterFrequencyMobilityPrinciples6.CapacityManagement4.Accessibility&MobilityPrinciples7.KPIs3OutlineLet’sgetusedwiththemainconceptsoftheHSDPA.HSDPAintroducesnewtechnologiesintheUMTSw
2、orldandconsequentlyanewwaytomanagePStraffic.Themostimportantimpactsofitareon:ModulationRetransmissionschemesSchedulingUsageofPowerandCodeThispresentationreportsanoverviewofthemainissuestotakeinmind.4HSDPABasicPrinciples51-SharedChannelTransmission(1/2)Shared-channeltransmissionimp
3、liesthatacertainamountofradioresourcesofacell(codesandpower)isseenasacommonresourcethatisdynamicallysharedbetweenusers.Theideaisthatapartofthetotaldownlinkcoderesourceisdynamicallysharedbetweenasetofpacket-datausers,primarilyinthetimedomain.Thecodesareallocatedtoauseronlywhentheya
4、reactuallytobeusedfortransmission,leadingtoefficientcodeandpowerutilization.ForP4only5codes(SF=16)willbeavailablefortheHSDPAfeatureandtheywillbesharedonatimebase.ChannelizationcodesallocatedforHS-DSCHtransmission5codes(example)SF=16SF=8SF=4SF=2SF=1User#1User#2User#3User#4TTIShare
5、dchannelizationcodes61-SharedChannelTransmission(2/2)TheShared-channeltransmissionallows:Higherpeakbitrate:alltheresourcecanbeallocatedtoasingleuserincaseoflowload.BetterapplicationperformancebeingclosertothemodelTCPhasbeingdesignedfor.Moreefficientutilizationofavailablecoderesour
6、cescomparedtotheuseofadedicatedchannel,i.e.reducedriskforcode-limiteddownlink.TheShared-channeltransmissionimpacts:Schedulingbecomemorecomplex72-Short2msTTI(1/2)TheTransmissionTimeIntervalbecomesextremelyshortinHSDPA;2mscomparedtothe10msusedbyR99highbitrateradiobearer.TheHSchannel
7、sareorganisedinsub-frameof3slotseach;thismeansthattheslottime2/3ms/slotisthesameasforR99slots(10/15ms/slot).Theschedulingandthelinkadaptationalgorithmsworkatthisfrequency!10ms20ms40ms80msEarlierreleases2msRel5(HS-DSCH)2ms82-Short2msTTI(2/2)TheshorterTTIallows:Reducedair-interfaced
8、elay:thisisrequiredbythetheTCPath
此文档下载收益归作者所有